package com.clare.gulimall.product.service.impl;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.Comparator;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.clare.common.utils.PageUtils;
import com.clare.common.utils.Query;

import com.clare.gulimall.product.dao.CategoryDao;
import com.clare.gulimall.product.entity.CategoryEntity;
import com.clare.gulimall.product.service.CategoryService;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> listWithTree() {
        // 1.查出所有分类
        List<CategoryEntity> entities = baseMapper.selectList(null);

        // 2.组装成父子的树形结构
        // 2.1 找到所有的一级分类  2.2 给一级分类设置children 2.3 一级分类排序
        List<CategoryEntity> level1Menus = entities.stream().
                filter(categoryEntity -> categoryEntity.getParentCid() == 0)
                .map((menu) -> {
                    menu.setChildren(getChildren(menu, entities));
                    return menu;
                })
                /*.sorted((menu1,menu2)->{
                    return (menu1.getSort()==null?0:menu1.getSort())-(menu2.getSort()==null?0:menu2.getSort());
                })*/
                // 空指针处理
                .sorted(Comparator.comparingInt(menu -> (menu.getSort() == null ? 0 : menu.getSort())))
                .collect(Collectors.toList());

        return level1Menus;
    }

    @Override
    public void removeMenuByIds(List<Long> catIds) {
        // TODO 检查当前删除的菜单，是否被别的地方引用
        baseMapper.deleteBatchIds(catIds);
    }

    /**
     * 递归查找所有菜单的子菜单
     *
     * @param root 根节点
     * @param all  所有的元素
     * @return {@link List<CategoryEntity>}
     * @author clare
     * @date 2020-11-22 16:50
     */
    private List<CategoryEntity> getChildren(CategoryEntity root, List<CategoryEntity> all) {
        List<CategoryEntity> children = all.stream()
                .filter(categoryEntity -> categoryEntity.getParentCid().longValue() == root.getCatId().longValue())
                .map((menu) -> {
                    menu.setChildren(getChildren(menu, all));
                    return menu;
                })
                .sorted(Comparator.comparingInt(menu -> (menu.getSort() == null ? 0 : menu.getSort())))
                .collect(Collectors.toList());
        return children;
    }

}